[PATCH] ipmi: use completions, not semaphores, in powerdown code

Don't use semaphores for IPC in the poweroff code, use completions instead.

Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>